Morphine

About morphine

Morphine is a strong painkiller. It's used to treat severe pain, for example after an operation or a serious injury, or pain from cancer or a heart attack.

It's also used for other types of long-standing pain when weaker painkillers no longer work.

Morphine is available only on prescription. It comes as tablets, capsules, granules that you dissolve in water, a liquid to swallow, suppositories (pellets inserted into the bottom) and as an injection. Morphine injections are usually only done in hospital.

Key facts

Morphine works by blocking pain signals from travelling along the nerves to the brain.
The most common side effects of morphine are constipation, feeling sick and sleepiness.
It's possible to become addicted to morphine, but this is rare if you're taking it to relieve pain under medical supervision.
It may be best not to drink alcohol while taking morphine as you're more likely to get side effects like feeling sleepy.
Morphine is also called by the brand names MST, Zomorph, Sevredol, Morphgesic, MXL or Oramorph.

Who can and can't take morphine

Morphine can be taken by children and adults of all ages. However babies, young children and older people are more likely to get side effects.

Morphine is not suitable for some people. Tell your doctor before starting the medicine if you have:

had an allergic reaction to morphine or any other medicines in the past
breathing difficulties
a lung problem
an addiction to alcohol
an illness which causes seizures
a head injury
low thyroid levels
adrenal gland problems
kidney or liver problems
an enlarged prostate
low blood pressure
myasthenia gravis (a rare illness that causes muscle weakness)

Morphine is generally not recommended in pregnancy. Tell your doctor before taking morphine if you're trying to get pregnant, are already pregnant or if you're breastfeeding.

How and when to take it

It's important to take morphine as your doctor has asked you to.

Take morphine with, or just after, a meal or snack so it's less likely to make you feel sick.

Different types of morphine

Morphine comes as:

tablets
capsules
granules (that you dissolve in water to make a drink)
a liquid that you swallow
suppositories
injection

Morphine suppositories are useful if you can't swallow tablets or liquids.

Morphine liquid, suppositories, injections and some morphine tablets and capsules are fast-acting. They're used for pain which is expected to last for a short time. Fast-acting morphine is often used when you start taking morphine to help find the right dose.

Morphine granules and some morphine tablets and capsules are slow-release. This means the morphine is gradually released into your body over either 12 or 24 hours. This type of morphine takes longer to start working but lasts longer. It's used for long-term pain.

Sometimes you may take both a fast-acting morphine and a slow-release morphine to manage long term pain and sudden flares of pain that break through the long-acting medicine.

Morphine does not come as a skin patch. However, there are skin patches containing morphine-like painkillers such as fentanyl.

How often will I take it?

How often you take it depends on the type of morphine that you've been prescribed.

You can choose to take your morphine at any time of day but try to take it at the same time every day and space your doses evenly. For example, if you take morphine twice a day and have your first dose at 8am, take your second dose at 8pm.

fast-acting tablets and capsules - usually 4 to 6 times a day
slow-release granules, tablets and capsules - usually 1 to 2 times a day
liquid - usually 4 to 6 times a day
suppositories - usually 4 to 6 times a day
injections - usually 4 to 6 times a day (sometimes in a pump that you control yourself)

It's important to swallow slow-release morphine tablets and capsules whole with a drink of water.

Do not break, crush, chew or suck morphine slow-release tablets or capsules. If you do, the slow-release system won't work and the whole dose might get into your body in one go. This could cause a potentially fatal overdose.

Will my dose go up or down?

Usually, you start on a low dose of morphine and this is increased slowly until your pain is well controlled.

Once your pain is under control, talk to your doctor about swapping to slow-release morphine. This may cut down the number of doses you have to take each day.

When you stop taking morphine your dose will go down gradually, especially if you've been taking it for a long time.

What if I forget to take it?

This will vary depending on which type of morphine you're taking.

If you forget to take a dose, check the information on the patient information leaflet inside the packaging or ask your pharmacist or doctor for advice on what to do.

Never take 2 doses at the same time to make up for a forgotten one.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to remember to take your medicine.

What if I take too much?

Taking too much morphine can be dangerous.

If you've taken an accidental overdose you may feel very sleepy, sick or dizzy. You may also find it difficult to breathe. In serious cases you can become unconscious and may need emergency treatment in hospital.

The amount of morphine that can lead to an overdose varies from person to person.

If you take too much morphine by accident, call your doctor or go to your nearest hospital A&E department straight away.

If you need to go to hospital, take the morphine packet or leaflet inside it plus any remaining medicine with you.

Where to store morphine

If you're prescribed morphine, it's particularly important that you:

store it properly and safely at home
keep it out of the sight and reach of children
never give your medicine to anyone else

Return any unused morphine to your pharmacist who will dispose of it.

Taking morphine with other painkillers

It's safe to take morphine with paracetamol, ibuprofen or aspirin.

Some everyday painkillers that you can buy over-the-counter from pharmacies contain codeine, which is a similar medicine to morphine. Codeine-containing painkillers from pharmacies include co-codamol, Nurofen Plus and Solpadeine.

Do not take codeine-containing painkillers that you can buy alongside prescribed morphine (and prescribed codeine). You will be more likely to get side effects.

Side effects

Like all medicines, morphine can cause side effects in some people but many people have no side effects or only minor ones.

The higher the dose of morphine the more chance that you will get side effects.

Common side effects

Common side effects happen in more than 1 in 100 people. Talk to your doctor or pharmacist if the side effects bother you or don't go away:

constipation
feeling and being sick
dizziness and vertigo (a sensation of spinning)
confusion
feeling sleepy
headaches
itchiness and rash

Serious side effects

Serious side effects happen in less than 1 in 100 people. Tell your doctor if you get:

heart problems
seizures
breathing difficulty or short shallow breathing
muscle stiffness
feel dizzy, tired and have low energy - this could be a sign of low blood pressure

Serious allergic reaction

In rare cases, it’s possible to have a serious allergic reaction to morphine.

A serious allergic reaction is an emergency. Contact a doctor straight away if you think you or someone around you is having a serious allergic reaction.

The warning signs of a serious allergic reaction are:

getting a skin rash that may include itchy, red, swollen, blistered or peeling skin
wheezing
tightness in the chest or throat
having trouble breathing or talking
swelling of the mouth, face, lips, tongue, or throat

These are not all the side effects of morphine. For a full list see the leaflet inside your medicines packet.

You can report any suspected side effect to the UK safety scheme.

How to cope with side effects

What to do about:

constipation - try to eat more high-fibre foods such as fresh fruit and vegetables and cereals. Try to drink several glasses of water or other non-alcoholic liquid each day. If you can, it may also help to do some gentle exercise. Speak to your doctor about medicine to help prevent or treat constipation caused by morphine if your symptoms do not go away.
feeling sick or vomiting - take morphine with or just after a meal or snack to ease feelings of sickness. This side effect should normally wear off after a few days. Talk to your doctor about taking anti-sickness medicine if it carries on for longer.
feeling sleepy, tired or dizzy - these side effects should wear off within a week or two as your body gets used to morphine. Talk to your doctor if they carry on for longer.

Don't take any other medicines to treat the side effects of morphine without speaking to your pharmacist or doctor.

Pregnancy and breastfeeding

Morphine is generally not recommended during pregnancy and while breastfeeding.

In early pregnancy, it's been linked to some problems for your unborn baby. If you take morphine at the end of pregnancy there's a risk that your newborn baby may get withdrawal symptoms or be born addicted to morphine.

However, it's important to treat pain in pregnancy. For some pregnant women with severe pain, morphine might be the best option. Your doctor is the best person to help you decide what's right for you and your baby.

For more information about how morphine can affect you and your baby during pregnancy see the BUMPS leaflet.

Morphine and breastfeeding

Morphine is not usually recommended if you're breastfeeding. Small amounts of morphine pass into breast milk and can cause breathing problems in the baby.

Tell your doctor if you're trying to get pregnant, are already pregnant or if you're breastfeeding.

Cautions with other medicines

Some medicines and morphine interfere with each other and increase the chance that you will have side effects.

Tell your doctor if you are taking any medicines:

to help you sleep
for depression - some types can't be taken with morphine
for high blood pressure
to help stop you feeling sick or vomiting
to treat symptoms of an allergy

Mixing morphine with herbal remedies and supplements

It's not possible to say that complementary medicines and herbal teas are safe to take with morphine. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.

Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.

Common questions

How does morphine work?

Morphine is from a group of medicines called opiates, or narcotics.

It works in the central nervous system and the brain to block pain signals to the rest of the body. It also reduces the anxiety and stress caused by pain.

When morphine blocks the pain, there are other unwanted effects – for example slow or shallow breathing. It also slows down digestion, which is why morphine can cause constipation.

How long will it take to work?

This depends on the type of morphine you take.

A morphine injection into a vein gives the quickest pain relief. It works almost straight away.

Fast-acting morphine taken by mouth works in 30 to 60 minutes but it wears off after a few hours. Slow-acting morphine taken by mouth can take a day or 2 to start working but the pain relief will last for longer.

It's difficult to say how long morphine suppositories take to work. It can be very different from one person to the next.

Can I become addicted to morphine?

Yes, morphine is addictive. But in reality, if you're taking it to relieve pain (rather than using it as a recreational drug) it's very unlikely you will get addicted to it because you're not taking it to get a high.

If you need to take morphine for a long time your body can become tolerant to it. That means you need higher doses to control your pain. This isn't usually a problem when you stop taking morphine. Withdrawal symptoms can be prevented by reducing the dose gradually.

How will I know if I'm addicted?

If you're addicted to morphine, you may find it difficult to stop taking it or feel you need to take it more often than necessary.

And if you stop taking morphine suddenly you may suffer from withdrawal symptoms. These include agitation, anxiety, nervousness, panic attacks, difficulty sleeping, shaking, over-activity, pins and needles or ringing in the ears.

Talk to your doctor if you're worried about addiction or if you want to know more about how to prevent withdrawal symptoms.

Will I get withdrawal symptoms when I stop taking it?

Morphine can cause unpleasant withdrawal symptoms when you come off it suddenly, such as:

feeling agitated
feeling anxious
shaking
sweating

If you want to stop taking morphine, talk to your doctor first. The dose can be reduced gradually so you don't get unpleasant withdrawal effects.

Is morphine a controlled medicine?

Morphine is a controlled medicine. This means there are strict rules on how it's prescribed and dispensed to make sure it's not given to the wrong person or misused.

When you collect morphine your pharmacist will ask for proof of your identity such as your passport or driving licence. You'll also be asked to sign the back of your prescription, to confirm that you've received it.

If you're collecting morphine for someone else, you're legally required to show the pharmacist proof of your identity if asked.

Can I drink alcohol with it?

Drinking alcohol while you're on morphine may make you feel more sleepy or increase the risk of serious side effects.

It's best to stop drinking alcohol during the first few days of treatment until you see how the morphine affects you.

If you feel sleepy with morphine, stop drinking alcohol while you are taking it.

Are there other painkillers I can try?

The type of painkiller that's best depends on what type of pain you have and the cause of your pain. If morphine doesn’t get rid of your pain or becomes less effective, discuss this with your doctor.

Will it make me so sleepy I can't function?

When you first take morphine, you'll probably feel sleepy for a few days. But the sleepiness will wear off after a few days as your body gets used to the medicine.

You might notice you are less alert. In this case, you might choose to have less than perfect pain relief as a trade-off.

Is morphine only used at the end of life?

Morphine isn't only used at the end of a terminal illness. It's the amount of pain you have, not the stage of your illness, that decides whether morphine is prescribed for you.

Can children take morphine?

Morphine can be used safely in babies and children of all ages, although the dose is usually lower than for adults.

Can I drive or ride a bike?

Morphine can make you feel sleepy or dizzy or give you blurred or double vision. If this happens to you, don't drive or ride a bike until you feel better.

Will recreational drugs affect it?

If you take recreational drugs, such as cannabis, cocaine and heroin, while you're taking morphine, you're more likely to get the serious side effects of morphine including breathing difficulties, heart problems, seizures and even going into a coma.

Some recreational drugs, such as cannabis, will also increase morphine side effects such as sleepiness and dizziness.

Taking heroin while you're on prescribed morphine is especially dangerous. You're more likely to get all the side effects of morphine, including addiction.

Tell your doctor if you think you may take recreational drugs while you're on morphine.